Orientite is a rare manganese silicate mineral typically occurring as small brown tabular crystals or radial clusters. It is highly valued by mineral collectors for its scarcity and is famously associated with manganese-rich deposits in Cuba and the Franklin Mining District.

Hardness
3.5-4
Mohs
Luster
Vitreous to Pearly
Streak
Yellowish Brown
Transparency
Translucent

Is this orientite?

5-step field check

Run through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.

  • 1
    Test the hardness
    Try to scratch orientite with a known reference. Orientite sits at Mohs 3.5-4 — softer than the next harder reference, harder than the previous one.
  • 2
    Check the streak
    Drag the specimen across an unglazed porcelain plate. Orientite leaves a yellowish brown streak.
  • 3
    Read the luster
    Hold the specimen under a strong light. Orientite typically shows a vitreous to pearly luster.
  • 4
    Match the color range
    Compare against the expected color range: brown, dark brown.
  • 5
    Look at form & habit
    Crystal system: orthorhombic. Typical habit: tabular crystals, radial aggregates.

Often confused with

Orientite vs. its common look-alikes — and how to tell them apart in the field.

Often found alongside orientite

Minerals reported to co-occur with orientite. Spotting these in float or country rock is a strong cue you are in the right ground.

All properties

Chemical formula
Ca₂Mn³⁺₆O₈(Si₄O₁₂)·4H₂O
Mohs hardness
3.5-4
Density
3.48 g/cm³
Streak
Yellowish Brown
Luster
Vitreous to Pearly
Transparency
Translucent
Crystal system
Orthorhombic
Crystal habit
Tabular Crystals, Radial Aggregates
Cleavage
Perfect On {010}
Rarity
Rare
Uses
Collector
Host rock
Manganese Deposits in Sedimentary or Metamorphic Environments
Typical price
$50-300 per specimen

Where rockhounds find orientite

Classic worldwide localities

  • Oriente Province, Cuba
  • Franklin, New Jersey, USA

Field-hunting tip

Look in manganese deposits in sedimentary or metamorphic environments country — that is the host setting where orientite typically forms. If you start seeing calcite, hausmannite, braunite in float, you are in the right ground. Field specimens usually show a tabular crystals, radial aggregates habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify orientite?+
Mohs hardness is 3.5-4. It typically shows a vitreous to pearly luster. The streak is yellowish brown. Common colors include brown, dark brown.
Where is orientite found?+
Notable localities include Oriente Province, Cuba; Franklin, New Jersey, USA.
How much is orientite worth?+
Typical asking prices fall in the range of $50-300 per specimen. Quality, size, and provenance can move individual specimens well outside that range.
What rocks look like orientite?+
Orientite is most often confused with Epidote, Piemontite. A quick hardness test and a streak check separate the look-alikes faster than color alone.
What minerals are found with orientite?+
Orientite commonly co-occurs with Calcite, Hausmannite, Braunite. Spotting any of these in float or country rock is a useful trip signal.
What kind of rock does orientite form in?+
Orientite typically forms in manganese deposits in sedimentary or metamorphic environments. Working float back to the host body is the standard way to chase a fresh occurrence.
What is orientite used for?+
Orientite is used in collector.

Find orientite on the map

RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.

Download on the App StoreGet it on Google Play